Physical process impact

The consequence of an attack here is not data loss. It is something moving, heating, overflowing or stopping.

That reframes everything downstream: severity, response, reporting and the people who need to be involved. A denial of service on a website is an outage. The equivalent on a process control network can damage equipment, spoil a batch, or hurt somebody, which is why the plant's engineers have to be in the incident rather than adjacent to it.